This invention relates to a remote signalling apparatus, particularly suitable for remote surveillance purposes.
Apparatus are known are remotely signalling the occurrence of particular events to be monitored, such as a theft, tampering, kidnapping, a variation in certain environment conditions, etc.
These known apparatus normally comprise a transmitter, activated by one or more sensors which detect the occurrence of the event to be monitored, and one or more receivers which receive the signal from the activated transmitter. If, for example, the event to be monitored is the attempted theft of a watercraft, a transmitter of known apparatus is installed onboard the craft, the sensors are conventional devices which detect the intrusion of an intruder and/or an attempted theft, and the receiver is an apparatus tuned to the transmitter frequency. When the driver abandons or leaves the craft, he carries with him the receiver, and if an attempted theft or tampering with the craft occurs, he receives, via such receiver, a suitable signal from the transmitter. Known apparatus also provide for corresponding signals to be fed to fixed points (guardhouses, surveillance stations, police, etc.), in order to increase the reliability and timeliness of the intervention of guard personnel or of personnel entrusted with surveillance.
These known apparatus have proven to be considerably effective, in that they immediately indicate the occurrence of an undesirable event, and thus enable the person concerned to intervene without delay. However, they also have certain drawbacks, which mainly relate to an uncertainty in the attribution of responsibility where it has not been possible to prevent the undesirable event from occurring. In this respect, because of the fact that there is no check or determination of the actual moment in time at which most of such undesirable events occur, the only source of reference for such information is the word of the directly responsible person of concern. This can give rise to a whole series of disputes, which arise in view of the difficulty, and often the impossibility, of proving any statement of such person. Moreover, practical experience continuously shows that when the occurred undesirable event is covered by insurance, such disputes are greater, and thus, the smaller the possiblity of irrefutably providing the facts of the event.
There is, therefore, the problem of remotely transmitting a set of information in an unequivocal manner, and at the same time, of providing certain proof of the fact that this information has been correctly received and recognized by a person for whom it is intended, and even by another who replaces such a person during a normal shift of work covering such tasks and the responsibilities connected therewith.
Referring again to the already stated example, a case could be that of a pleasure craft which on being moored is entrusted to the custody of a harbor guard. Up to that moment of entrustment, the responsibility for the craft is obviously in the hands of the driver of such craft, whereas from that moment onward, the responsibility is transferred to the harbor guard, who, in the same manner as the driver, must be able to receive, from correctly operating apparatus, suitable signals as to when an undesirable event such as flooding, the commencement of fire, the entry of intruders, attempts to destroy or pilfer the cargo, attempts to remove the craft, etc., occurs. Each responsibile person must also, obviously, be in a position to determine from which of the crafts in his care the various signals originate.